Now that Red Hat has released RHEL 7 with systemd in place of the erstwhile SysVinit, it appears that the end of the world is indeed approaching. A schism and war of egos is unfolding within the Linux community right now, and it is drawing blood on both sides. Ultimately, no matter who "wins," Linux looks to lose this one.
The idea behind systemd was to replace the aged Init functionality and provide a sleek, common system initialization framework that could be standardized across multiple Linux distributions. systemd promised to speed up system boot times, better handle race conditions, and in general, improve upon an item that wasn't exactly broken, but wasn't as efficient as it could be.
As an example, you might be able to produce software that could compile and run on numerous Linux distributions, but if it had to start at boot time, you could be required to write several different Init-style boot scripts, one for each supported distribution. Clearly this is inelegant and could use improvement.
Also, there was the problem that traditional Init is slow and bulky, based on shell scripts and somewhat random text configuration files. This is a problem on systems that need to boot as fast as possible, like embedded Linux systems, but is much less of a problem on big iron that takes longer to count RAM in POST than it does to boot to a log-in prompt. However, it's hard to argue that providing accelerated boot times for Linux across the board is not a good thing.
These are all laudable goals, and systemd wasn't the first project aimed at achieving them. It is, however, the first such project to gain mainstream acceptance. This is in no small part due to the fact that the main developers of systemd are employed by Red Hat, which is still the juggernaut of Linux distributions.
Red Hat exerted its considerable force on the Linux world. Thus, we saw systemd take over Fedora, essentially become a requirement to run the GNOME desktop, then become an inextricable part of a significant number of other distributions (notably not the "old guard" distributions such as Gentoo). Now you'd be hard-pressed to find a distribution that doesn't have systemd in the latest release (Debian doesn't really use systemd, but still requires systemd-shim and CGManager).
While systemd has succeeded in its original goals, it's not stopping there. systemd is becoming the Svchost of Linux -- which I don't think most Linux folks want. You see, systemd is growing, like wildfire, well outside the bounds of enhancing the Linux boot experience. systemd wants to control most, if not all, of the fundamental functional aspects of a Linux system -- from authentication to mounting shares to network configuration to syslog to cron. It wants to do so as essentially a monolithic entity that obscures what's happening behind the scenes.